Problem: On the way to school, Karen became fixated on the puzzle game on her phone!

<image>

The game is played as follows. In each level, you have a grid with n rows and m columns. Each cell originally contains the number 0.

One move consists of choosing one row or column, and adding 1 to all of the cells in that row or column.

To win the level, after all the moves, the number in the cell at the i-th row and j-th column should be equal to gi, j.

Karen is stuck on one level, and wants to know a way to beat this level using the minimum number of moves. Please, help her with this task!

Input

The first line of input contains two integers, n and m (1 ≤ n, m ≤ 100), the number of rows and the number of columns in the grid, respectively.

The next n lines each contain m integers. In particular, the j-th integer in the i-th of these rows contains gi, j (0 ≤ gi, j ≤ 500).

Output

If there is an error and it is actually not possible to beat the level, output a single integer -1.

Otherwise, on the first line, output a single integer k, the minimum number of moves necessary to beat the level.

The next k lines should each contain one of the following, describing the moves in the order they must be done:

  * row x, (1 ≤ x ≤ n) describing a move of the form "choose the x-th row". 
  * col x, (1 ≤ x ≤ m) describing a move of the form "choose the x-th column". 



If there are multiple optimal solutions, output any one of them.

Examples

Input

3 5
2 2 2 3 2
0 0 0 1 0
1 1 1 2 1


Output

4
row 1
row 1
col 4
row 3


Input

3 3
0 0 0
0 1 0
0 0 0


Output

-1


Input

3 3
1 1 1
1 1 1
1 1 1


Output

3
row 1
row 2
row 3

Note

In the first test case, Karen has a grid with 3 rows and 5 columns. She can perform the following 4 moves to beat the level:

<image>

In the second test case, Karen has a grid with 3 rows and 3 columns. It is clear that it is impossible to beat the level; performing any move will create three 1s on the grid, but it is required to only have one 1 in the center.

In the third test case, Karen has a grid with 3 rows and 3 columns. She can perform the following 3 moves to beat the level:

<image>

Note that this is not the only solution; another solution, among others, is col 1, col 2, col 3.

Solution (in PYTHON3):

Solution:
import math as mt 
import sys,string
input=sys.stdin.readline
import random
from collections import deque,defaultdict
L=lambda : list(map(int,input().split()))
Ls=lambda : list(input().split())
M=lambda : map(int,input().split())
I=lambda :int(input())
n,m=M()
l=[]
x=[]
req=[]
req2=[]
ans=[]
ans2=[]
def check(l,r):
    for i in range(len(l)):
        if(l[i]!=r[i]):
            return False
    return len(l)==len(r)
    
c=0
f=0
c2=0
for i in range(n):
    l.append(L())
    k=min(l[-1])
    if(k>0):
        ans.append(("r",i+1,k))
        req.append([k]*m)
        c+=k
    else:
        req.append([0]*m)
for i in range(n):
    for j in range(m):
        if(l[i][j]!=req[i][j]):
            e=l[i][j]-req[i][j]
            c+=e
            for k in range(n):
                req[k][j]+=e
            ans.append(("c",j+1,e))
                #print(e,"E")

if(check(req,l)):
    f=1
for i in range(n):
    req2.append([0]*m)
for i in range(m):
    k=10**10
    for j in range(n):
        k=min(k,l[j][i])
    if(k>0):
        for p in range(n):
            req2[p][i]=k
        c2+=k
        ans2.append(("c",i+1,k))
for i in range(n):
    for j in range(m):
        if(l[i][j]!=req2[i][j]):
            e=l[i][j]-req2[i][j]
            c2+=e
            for k in range(m):
                req2[i][k]+=e
            
            ans2.append(("r",i+1,e))
if(check(req2,l)):
    f+=2
if(f==3):
    print(min(c,c2))
    if(c<c2):
        for i in range(len(ans)):
            if(ans[i][0]=="c"):
                for k in range(ans[i][2]):
                    print("col",ans[i][1])
            else:
                for k in range(ans[i][2]):
                    print("row",ans[i][1])
    else:
        for i in range(len(ans2)):
            if(ans2[i][0]=="c"):
                for k in range(ans2[i][2]):
                    print("col",ans2[i][1])
            else:
                for k in range(ans2[i][2]):
                    print("row",ans2[i][1])
elif(f==1):
    print(c)
    for i in range(len(ans)):
        if(ans[i][0]=="c"):
            for k in range(ans[i][2]):
                print("col",ans[i][1])
        else:
            for k in range(ans[i][2]):
                print("row",ans[i][1])
elif(f==2):
    print(c2)
    for i in range(len(ans2)):
        if(ans2[i][0]=="c"):
            for k in range(ans2[i][2]):
                print("col",ans2[i][1])
        else:
            for k in range(ans2[i][2]):
                print("row",ans2[i][1])
else:
    print(-1)